Abstract
.How neurovascular coupling develops in preterm-born neonates has been largely neglected in scientific research. We measured visually evoked (flicker light) hemodynamic responses (HRs) in preterm-born neonates (, gestational age: weeks, postnatal age: days) at the visual cortex (VC) and left frontotemporal lobe (FTL) using functional near-infrared spectroscopy (fNIRS) neuroimaging. We found that the HR characteristics show a large intersubject variability but could be classified into three groups according to the changes of oxyhemoglobin concentration at the VC [(A) increase, (B) decrease, or (C) inconclusive]. In groups A and B, the HRs at the left FTL were correlated with those at the VC, indicating the presence of a frontotemporal–occipital functional connectivity. Neonates in group A had a higher weight at measurement compared to those in group B, and had the lowest baseline total hemoglobin concentration and hematocrit compared to group C. To the best of our knowledge, this is the first fNIRS study showing (1) that the HRs of preterm-born neonates need to be classified into subgroups, (2) that the subgroups differed in terms of weight at measurement, and (3) that HRs can be observed also at the FTL during visual stimulation. These findings add insights into how neurovascular coupling develops in preterm-born neonates.
Highlights
Brain activity is associated with physiological changes, which alter the optical properties of tissue
The difference we found between these two brain regions was that in the visual cortex (VC) the hemodynamic change was more robust with an increase or decrease in Δ1⁄2O2Hb, whereas in the frontotemporal lobe (FTL) the answer was more biphasic with slight increase followed by a decrease in Δ1⁄2O2Hb in group A and in group B just the opposite direction (Fig. 3)
(3) The characteristics of the hemodynamic responses (HRs) at the VC was used to subgroup the neonates into three groups [positive (A) or negative (B) HR, or absence (C) of a HR]. (4) The subgrouping of the neonates according to the HR characteristics was correlated with differences in the weight of the neonate at measurement
Summary
Brain activity is associated with physiological changes, which alter the optical properties of tissue. Neuroimaging with fNIRS has the potential to provide insights into the origin of neonatal brain lesions, as well as into functional development of both the normal and the abnormal brain.[2,3] The ability of fNIRS to access neurovascular coupling associated with neuronal activity offers a useful opportunity to investigate, for example, the neural basis of visual cognitive development in infants.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
